Hard to put a figure on it. Depends on fuel and oil quality, air filter/oil quality, ambient conditions and how hard you thrash it


I have heard of Go 5 and 7 ports doing upwards of 10 gallons, so I would assume the 3 RSpec would be in the same catagory. The 3 Sport maybe not quite as long, as the initial pinch is nowhere near as much as the Pro series engines. I would be very surprised if you got less than 8 gallons out of a well looked after Pro Series engine.